1. Field of the Invention
This invention pertains generally to rope climbing devices, and more particularly to powered rope climbing devices or powered ascenders.
2. Description of Related Art
Climbing devices are used to enable a person to ascend or descend a rope or cable. There are many examples where a climbing device is needed that can be operated by the person ascending the rope, such as mountain climbing, caving, tree trimming, rescue operations and military operations. Industrial uses of a climbing device may include scaling tall structures, towers, poles, mine shafts or bridge works for servicing, cleaning, window washing, painting, etc.
Manual lifting devices, also known as ascenders, are configured to grip a vertical tensioned rope when load is present and to slide when the load is released. Typically, an individual must be capable of repetitively lifting their own weight on the manual ascender when climbing with these devices.
Powered personal lifting devices assist personnel in scaling vertical surfaces. Motorized winches are used to raise or lower personnel on platforms or harnesses attached to ropes. A winch must be anchored to a solid platform above the load or use pulleys coupled to the platform to hoist the load. Further, a winch winds the rope or cable on a spool which limits the length and weight of rope that can be used. Hoists, usually with compound pulleys or reducing gears are used to raise or lower individuals or platforms and must be suspended from a secure support point such as a tripod, beam or bridge crane. Typically a winch or hoist requires at least a second person to operate or control the device in order for a first person to safely ascend a rope.
Portable, climber operated winches are limited by bulky power delivery systems and associated weight of the spool.
Safety is a paramount concern when a person is ascending a rope. Failure of a component that results in a rapid descent or fall will result in injury or death. Existing ascenders typically have cams, jam cleats or other braking devices that will engage if a sudden or rapid descent is detected. These devices can cause a sudden stop with resulting injury or equipment damage. A lightweight powered rope ascender with means to brake during ascent, to hold a position on a rope and to descend in a controlled manner is needed.